I strongly beleive that teachers are sometimes looked at as confidants to a student. I dont know how many times i have been approached by a student with concerns...whether they are classroom-related or personal. I tend to draw a line with the personal stuff like "sorry i was not really into the class today, i had a bad argument with my girlfriend earlier and i don't know what to do about her."
What are your ways to spin that so you dont sound like you dont care but to not get involved with their personal issues?